About Agent and Controller Compatibility

A monitored environment may have agents of different versions deployed in it at a given time, as long as all agents are compatible with the Controller version. However, the oldest agents should be on originating tiers of any business transactions. This ensures that agents on downstream nodes can process the correlation header created by the originating tier.

It's an important point to consider when rolling out agent upgrades—be sure to start upgrading the agents on the nodes of downstream tiers first, and then upgrade the agents on the originating tier nodes last.

Language Agent Backward Compatibility

Starting in release 4.5, AppDynamics language agents are backward-compatible with any 4.4.1 or higher Controller. This enables you to upgrade your language agents – and take advantage of the latest agent-side enhancements, features, and bug fixes – without upgrading your 4.4 Controller. The following table outlines the Controller and language agent releases that are compatible.

Controller Release

Language Agent Release

Notes

4.4.1+

4.1+

4.4.1 and newer Controllers can accept connections from newer agents.

4.3.x

4.1.x – 4.3.x

4.3.x Controllers cannot accept connections from newer agents.

4.2.x

4.1.x – 4.2.x

Agents older than 4.3 are no longer supported, and agents older than 4.1 are no longer guaranteed to connect to a Controller.

Backward compatibility is supported on the following agents starting in Release 4.5:

Network Agent Compatibility

The 4.5.x Controller supports the following version of the Network Agent:

4.5.x

4.4.x

SSL Compatibility between Java Agent and Controller

The default protocol used by the Controller is TLSv1.2.

For the Java Agent, the default protocols are:

For Java 8 SE applications: TLSv1.2.

For Java 7+ applications: TLSv1.2. You can change the agent to use SSLv3 if desired. See Secure the Platformfor information on changing the default security protocol used by the Controller or agent.

For Java 5/6 applications: SSLv3. You must enable SSLv3 connection on the Controller if the agents connect directly to the Controller. See Secure the Platformfor information on changing the default security protocol used by the Controller or agent.

Introduction of New Agent Features

Even when new and old agents are supported by the same up-to-date Controller, new functionality introduced by later agents is not available on the older agents.

Information about when an agent feature was introduced is documented in the New and Enhanced Features section for a new major release (such as 4.5) and <minor_release_number> Updates sections for minor releases in the release notes.